As an example of a rotation transmission mechanism that transmits torque without contact, conventional magnetic coupling devices are known in which permanent magnets are arranged on the inner circumferential surface of a cylindrical drive rotating member and the outer circumferential surface of a cylindrical rotating driven member provided on the same rotation axis as of the drive rotating member so as to be opposed to each other through an air gap between the surfaces and in which torque from the drive rotating member is transmitted to the driven rotating member using the magnetic force that is generated between the inner circumferential surface and the outer circumferential surface (for example, Patent document 1).    Patent Document 1: Japanese Laid-open Patent Publication No. 2001-165189